x86/entry: Convert Invalid Opcode exception to IDTENTRY

Convert #UD to IDTENTRY:
  - Implement the C entry point with DEFINE_IDTENTRY
  - Emit the ASM stub with DECLARE_IDTENTRY
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code
  - Fixup the FOOF bug call in fault.c
  - Remove the old prototypes

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134904.955511913@linutronix.de

arch/x86/entry/entry_32.S

@@ -1325,13 +1325,6 @@ SYM_CODE_START(native_iret)
 SYM_CODE_END(native_iret)
 #endif
 
-SYM_CODE_START(invalid_op)
-	ASM_CLAC
-	pushl	$0
-	pushl	$do_invalid_op
-	jmp	common_exception
-SYM_CODE_END(invalid_op)
-
 SYM_CODE_START(coprocessor_segment_overrun)
 	ASM_CLAC
 	pushl	$0

arch/x86/entry/entry_64.S

@@ -1073,7 +1073,6 @@ apicinterrupt IRQ_WORK_VECTOR			irq_work_interrupt		smp_irq_work_interrupt
  */
 
 idtentry	X86_TRAP_BP		int3			do_int3				has_error_code=0
-idtentry	X86_TRAP_UD		invalid_op		do_invalid_op			has_error_code=0
 idtentry	X86_TRAP_NM		device_not_available	do_device_not_available		has_error_code=0
 idtentry	X86_TRAP_OLD_MF		coprocessor_segment_overrun	do_coprocessor_segment_overrun	has_error_code=0
 idtentry	X86_TRAP_TS		invalid_TSS		do_invalid_TSS			has_error_code=1

arch/x86/include/asm/idtentry.h

@@ -80,5 +80,6 @@ static __always_inline void __##func(struct pt_regs *regs)
 DECLARE_IDTENTRY(X86_TRAP_DE,		exc_divide_error);
 DECLARE_IDTENTRY(X86_TRAP_OF,		exc_overflow);
 DECLARE_IDTENTRY(X86_TRAP_BR,		exc_bounds);
+DECLARE_IDTENTRY(X86_TRAP_UD,		exc_invalid_op);
 
 #endif

arch/x86/include/asm/traps.h

@@ -14,7 +14,6 @@
 asmlinkage void debug(void);
 asmlinkage void nmi(void);
 asmlinkage void int3(void);
-asmlinkage void invalid_op(void);
 asmlinkage void device_not_available(void);
 #ifdef CONFIG_X86_64
 asmlinkage void double_fault(void);
@@ -38,7 +37,6 @@ asmlinkage void simd_coprocessor_error(void);
 asmlinkage void xen_xennmi(void);
 asmlinkage void xen_xendebug(void);
 asmlinkage void xen_int3(void);
-asmlinkage void xen_invalid_op(void);
 asmlinkage void xen_device_not_available(void);
 asmlinkage void xen_double_fault(void);
 asmlinkage void xen_coprocessor_segment_overrun(void);
@@ -59,7 +57,6 @@ asmlinkage void xen_simd_coprocessor_error(void);
 dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
 dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
 dotraplinkage void do_int3(struct pt_regs *regs, long error_code);
-dotraplinkage void do_invalid_op(struct pt_regs *regs, long error_code);
 dotraplinkage void do_device_not_available(struct pt_regs *regs, long error_code);
 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
 dotraplinkage void do_coprocessor_segment_overrun(struct pt_regs *regs, long error_code);
@@ -84,6 +81,11 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s);
 void __init trap_init(void);
 #endif
 
+#ifdef CONFIG_X86_F00F_BUG
+/* For handling the FOOF bug */
+void handle_invalid_op(struct pt_regs *regs);
+#endif
+
 static inline int get_si_code(unsigned long condition)
 {
 	if (condition & DR_STEP)

arch/x86/kernel/idt.c

@@ -76,7 +76,7 @@ static const __initconst struct idt_data def_idts[] = {
 	INTG(X86_TRAP_DE,		asm_exc_divide_error),
 	INTG(X86_TRAP_NMI,		nmi),
 	INTG(X86_TRAP_BR,		asm_exc_bounds),
-	INTG(X86_TRAP_UD,		invalid_op),
+	INTG(X86_TRAP_UD,		asm_exc_invalid_op),
 	INTG(X86_TRAP_NM,		device_not_available),
 	INTG(X86_TRAP_OLD_MF,		coprocessor_segment_overrun),
 	INTG(X86_TRAP_TS,		invalid_TSS),

arch/x86/kernel/traps.c

@@ -231,6 +231,21 @@ DEFINE_IDTENTRY(exc_overflow)
 	do_error_trap(regs, 0, "overflow", X86_TRAP_OF, SIGSEGV, 0, NULL);
 }
 
+#ifdef CONFIG_X86_F00F_BUG
+void handle_invalid_op(struct pt_regs *regs)
+#else
+static inline void handle_invalid_op(struct pt_regs *regs)
+#endif
+{
+	do_error_trap(regs, 0, "invalid opcode", X86_TRAP_UD, SIGILL,
+		      ILL_ILLOPN, error_get_trap_addr(regs));
+}
+
+DEFINE_IDTENTRY(exc_invalid_op)
+{
+	handle_invalid_op(regs);
+}
+
 #define IP ((void __user *)uprobe_get_trap_addr(regs))
 #define DO_ERROR(trapnr, signr, sicode, addr, str, name)		   \
 dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	   \
@@ -238,7 +253,6 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	   \
 	do_error_trap(regs, error_code, str, trapnr, signr, sicode, addr); \
 }
 
-DO_ERROR(X86_TRAP_UD,     SIGILL,  ILL_ILLOPN,   IP, "invalid opcode",      invalid_op)
 DO_ERROR(X86_TRAP_OLD_MF, SIGFPE,           0, NULL, "coprocessor segment overrun", coprocessor_segment_overrun)
 DO_ERROR(X86_TRAP_TS,     SIGSEGV,          0, NULL, "invalid TSS",         invalid_TSS)
 DO_ERROR(X86_TRAP_NP,     SIGBUS,           0, NULL, "segment not present", segment_not_present)

arch/x86/mm/fault.c

@@ -426,7 +426,7 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
 		nr = (address - idt_descr.address) >> 3;
 
 		if (nr == 6) {
-			do_invalid_op(regs, 0);
+			handle_invalid_op(regs);
 			return 1;
 		}
 	}

arch/x86/xen/enlighten_pv.c

@@ -624,7 +624,7 @@ static struct trap_array_entry trap_array[] = {
 	{ page_fault,                  xen_page_fault,                  false },
 	TRAP_ENTRY(exc_divide_error,			false ),
 	TRAP_ENTRY(exc_bounds,				false ),
-	{ invalid_op,                  xen_invalid_op,                  false },
+	TRAP_ENTRY(exc_invalid_op,			false ),
 	{ device_not_available,        xen_device_not_available,        false },
 	{ coprocessor_segment_overrun, xen_coprocessor_segment_overrun, false },
 	{ invalid_TSS,                 xen_invalid_TSS,                 false },

arch/x86/xen/xen-asm_64.S

@@ -35,7 +35,7 @@ xen_pv_trap int3
 xen_pv_trap xennmi
 xen_pv_trap asm_exc_overflow
 xen_pv_trap asm_exc_bounds
-xen_pv_trap invalid_op
+xen_pv_trap asm_exc_invalid_op
 xen_pv_trap device_not_available
 xen_pv_trap double_fault
 xen_pv_trap coprocessor_segment_overrun